Problem: Gabriela did 45 more sit-ups than Brandon in the evening. Gabriela did 69 sit-ups. How many sit-ups did Brandon do?
Explanation: Gabriela did 69 sit-ups, and Brandon did 45 fewer than that, so find the difference. The difference is $69 - 45$ sit-ups. She did $69 - 45 = 24$ sit-ups.